Nusinersen Beneficial in Later-Onset Spinal Muscular Atrophy

WEDNESDAY, Feb. 14, 2018 (HealthDay News) -- Nusinersen is associated with significant and clinically meaningful improvement in motor function among children with later-onset spinal muscular atrophy (SMA), according to a study published in the Feb. 15 issue of the New England Journal of Medicine.

Eugenio Mercuri, M.D., Ph.D., from Catholic University in Rome, and colleagues conducted a double-blind, sham-controlled phase 3 trial of nusinersen in 126 children with SMA with symptom onset after 6 months of age. Participants were randomized to undergo intrathecal administration of nusinersen or a sham procedure on days one, 29, 85, and 274 in a 2-to-1 ratio.

In the prespecified interim analysis, the researchers found that there was a least-squares mean increase from baseline to month 15 in the Hammersmith Functional Motor Scale-Expanded (HFMSE) score in the nusinersen group (by 4.0 points) and a decrease in the control group (by 1.9 points), with a significant between-group difference favoring nusinersen (least-squares mean difference in change, 5.9 points). The trial was terminated early based on this result; consistent results were seen in the final analysis. In the final analysis, 57 and 26 percent of children in the nusinersen and control groups, respectively, had an increase from baseline to month 15 in the HFMSE score of at least 3 points.

"Among children with later-onset SMA, those who received nusinersen had significant and clinically meaningful improvement in motor function as compared with those in the control group," the authors write.

The study was funded by Biogen (the manufacturer of nusinersen) and Ionis Pharmaceuticals.